The invention relates to fixing a cutting tool assembly to cutting tool machinery.
This invention is related to the field of earth working bit tools such as those used on machines for cutting rock or coal or machines for road building and road maintenance. The driven cutting tools are driven on machines to dislodge the bedded materials. In mining machines such as continues miners, road working machines like road planers and earth moving machines such as mechanized shovels a plurality of cutting bits are mounted on these apparatus for cutting earth strata or man made surfaces such as asphalt, pavement or concrete. The bits are moved by moving means such as a rotating wheel, chain, rotating arm or rotating drum. Mining machines themselves are of various types including undercutting machines, continues mining machines and long wall mining machines. The bits generally include a bit holder block for holding the cutting tool. The bit tools are mounted on a bit holder blocks that can be directly connected to the driven mining/construction machinery. The bit holder blocks are subject to wear and must be periodically replaced. The bit holder blocks on mining machinery and construction equipment are directly welded onto said machinery and equipment.
The cutting bit tools during operation are subjected to large loads. The large load may be the result of the cutting bit coming into contact with an underground obstacle like a manhole cover, bridge expansion joint or rail in construction or a pure grade ore such as copper in mining. The bit holder support block may be knocked off from the cutting machinery if the weld is not sufficiently strong.
Cutting tool bits in both the mining and construction industries have head tips made from cemented tungsten carbide and are generally conical in shape. In both industries the cutting bit tools are mounted on driven chains or rotary drums. The loads on both chains and drum type cutting tools are large and requires that the bit holder block be durably connected to the driven machinery.
U.S. Pat. Nos. 4,728,153 and 5,647,642 illustrate cutting tool assemblies in which the bit holder block is welded onto a rotary drum.
UK patent 1,044,926 discloses a first bit holder block that is welded to a rotary drum shown in FIG. 6 wherein the bottom contact surface of the bit holder block is correspondingly curved to permit it to be welded onto curved driven machinery. In FIG. 17 of UK 1,044,926 a bit holder block is shown having a flat contact surface for being welded onto a chain drive flat plate.
Construction companies and mining companies that operate both rotary drum and chain driven cutting equipment must maintain separate inventories of bit holder blocks for both chain driven equipment and rotary drums.
There is a need in the industry for a universal bit holder block that can be adequately welded onto a chain or rotary drum to withstand large loads and torques.
According to the present invention a bit holder block that can be durably connected to both a driven chain and rotary drum is disclosed. The bit holder block is designed to enable it to be welded to either a rotary drum or driven chain so as to withstand large loads that occur in mining and construction.
Two coplanar flat surfaces on opposite sides of a central curved section provide for easy welding to chains and provide for effective two line contact mounting on a drum for welding.
Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.